Asphalt mixer



Oct. 4, 1932; Q. SIFTON 3,389,287

ASPHALT MIXER Filed 001;. 6, 1928 s Sheets-Sheet 1 IN VEN TOR.

A TTORNEY Oct. 41-, 1932. Q SIFTON 1,889,287

ASPHALT MIXER Filed Oct. 6. 1928 s Sheets-Sheet 2 ATTORNEY mmm Get. 4, 1932.

c. sIFTQN ASPHALT MIXER Filed Oct. 6, 1928 3 Sheets-Sheet 3 INVENTOR. f/ff/o 99/70.

ATTORNEY Patented Oct. 4, 1932 UNITED STATES PATENT OFFICE A CLIFFORD SIFTON, OF LOS .A'NGELES, CALIFORNIA, ASSIGNOR TO CARL PLEASANT,

OF TULSA, OKLAHOMA ASPHALT MIXER Application filed October 6, 1928. Serial No. 310,800.

My inventionrelates to material feeding devices and more particularly to devices of that character for proportionately and periodically delivering predetermined quantities of a material such as a component of a paving mixture, the principal ob ects of the invention being to deliver measured proportionate quantities of a plurality of materials to assure constant relation between the amounts of the several materials being delivered, and to vary the relations between the amounts of materials being delivered whereby a desired combination of a plurality of materials may be assured.

The invention will be described as applied to apparatus for proportionately delivering the several ingredients of a pavlng mixture and combining the same, for convenient illustration of the structure and function of the parts. In preparing mixtures or aggregates such as those used for asphalt paving, the components include sand, a filler, liquid asphalt, and crushed stone. The sand is seldom available in a. single body adapted for incorporation in the mixture, and OIdlnarily two or more grades of sand are proportioned and mixed bv workmen using ordinary tools and roughly approximating the desired proportions of sand of the several grades. Other elements of the mixture are usually similarly introduced whereby the quantit es of the several ingredients may vary substantially from the proper proportions and the ingredients may lack the proper mixinrr for delivery to the. work.

It is therefore a further object of the invent on to assure the pro er assembly of the several ingredients in suitable condition for producing a paving mixture for delivery to the work.

In accomplishing these and other objects of the invention, I have provided improved details of structure the preferred forms of which are illustrated in the accompanying drawings, wherein:

Fig. 1 is a vertical cross sectional view of the apparatus showing a hopper, proportionate delivery means, and conveying apparatus.

Fig. 2 is the front elevation illustrating the relations between a plurality of material feeding devices.

Fig. 3 is a vertical central section through the lower portion of a hopper and feeding means illustrating a feeding shelf in retracted position.

Fig. 4 is a similar view illustrating a feeding shelf in advanced position.

Fig. 5 is a similar View illustrating the feeding shelf in process of return to retracted position for permitting material to fall into a chute.

Fig. 6 is a plan view of the bottom of the apparatus and the proportionate feeding means.

Fig. 7 is a front elevational view of a modified form of feeder actuating mechanism, showing a hopper, bottom, and feeding plates.

Referring in detail to the drawings:

In the illustrated-application of the invention, 1 designates a frame supported on posts 2 and suspended from the frame 1 by rods 3 is a material containing element 4. The frame is preferably positioned adjacent a pit 5 and extends downwardly in the pit for convenient dumping of material into the con tainer from carriers. A receiver 6 at the bottom of the pit receives material from the container 4. A plurality of hoppers or bins are provided in the container, for example three designated 7, 8, and 9 which are preferably similarly constructed and equipped, and may be formed by division walls 10 extending from front to back across the container, the front wall of the container comprising the front walls of the hoppers.

Each hopper has a bottom member 11 provided with an opening 12, and a sliding plate 13 is reciprocably supported by means presently described, below the opening to receive and support material contained in the hopper. Edges such as 14 of the plate extend a suflicient distance laterally and rearwardly over the bottom so that the plate may be moved forwardly and backwardly and continue to close the opening.

The hoppers have relatively large bottom ends so that the material, especially when consisting of large portions or when wet,

may move freely to the bottoms 11, and will not tend to pack.

An outlet port 15 is provided in the front wall of the hopper cutting the lower edge thereof and thus communicating with the bottom opening, through which material may pass from the hopper, and the plate 13 has a forwardly extended portion 16 for supporting the portions of material that pass through the outlet, the plate being adapted to translate material outwardly from the hopper upon forward movement and when retracted to withdraw support from the outwardly moved portion of the material so that the same may fall to a chute 17 preferably extending into the receiver 6 comprising a recess in the pit.

A shutter 18 slidable in guides 19 attached to the front wall of the hopper is movable vertically over the outlet by a screw 20 supported in a boss 21 mounted on the hopper to vary the effective opening of the outlet.

The plate is preferably supported on rollers 22 and 23 rotatably mounted on shafts 24 and 25 supported by hangers 26 secured to the hopper. A bracket 27 secured to the bottom of the plate carries a stud 28 on which is pivotally mounted one end of a pitman 29 having its opposite end mounted on a. crank pin 30 eccentrically positioned on a disk as presently described whereby rotation of the disk will cause the pitman to move the plate reciprocably.

Because of the free movement of material through the hopper to the bottom, the material is always piled equally over the reciprocating plate, and the equally exerted downward pressure of material assures passage of material through the side port. Further, the structure provides that downwardly pressing material in the hopper will prevent return of any material with the returning plate, and enforce the removal of a measured quantity from the retractively-moving plate.

Referring to the driving mechanism for the plates in the apparatus illustrated, disks 31 are fixed respectively to the outer ends of two aligned shafts 32 and 33 rotatably supported on hearing posts 34 (Fig. 1), the crank pins for the plates of the hoppers 7 and 9 being mounted in said disks 31. The shaft 33 is rotated from the shaft 32 by the crank pin for the plate of the hopper 8 which connects a disk 35 on the inner end of the shaft 32 with a disk 36 on the inner end of the shaft 33, as illustrated in Fig. 6.

The crank pins are preferably staggered on the several disks, whereby the plates will be moved in alternating relation.

Clutch mechanism designated 37 connects the actuating mechanism with the shaft 32, and the clutch is controlled by a rod 38.

When a plurality of hoppers are supported in a single frame the bottoms may comprise a single plate as shown in Fig. 6, and chutes 17 may conduct materials to a common throat 39 for delivery into the receiver 6.

A conveyor generally designated 40 is positioned so that its bucket 41 may receive the assembled aggregate from the chute throat for transferring the aggregate.

In the additional and modified plate actuating mechanism illustrated in Fig. 7, a shaft 42 is rotatably mounted in brackets 43 on a base 44, and arms 45 each having one end fixed to the shaft 42 carry a shaft 46 movably mounted in pairs of brackets 47 depending from the plates. The pitmen 29 are then mounted on the shaft 46 for conferring the reciprocablc movement on the plates, whereby when the plates move back and forth they are also given a slight up and down motion due to the swinging movement of the supporting arms 45 for compacting and releasing the material in the hoppers and thus agitating the aggregate to prevent clogging thereof in the openings.

In using the apparatus, the materials are delivered as required to the several hoppers. The regulating gates are adjusted for passage of predetermined quantities of naterial through the outlets when the reciprocating bottom plates move outw rdly. The actuating mechanism is set ation and the pitmen will respectively reciprocate the bottom plates to alternately move the plates outwardly from the hoppers for advancing portions of the materials and return the plates to permit the materials thus measured and advanced to fall to the chutes.

When a plate moves outwardly the lower edge of the adjustable control gate limits the amount of material that may be moved, and the material in the hopper falling to replace the outwardly moved quantity prevents return of the outwardly moved material by the plate when the latter is moved inwardly of the hopper.

The apparatus may be so adjusted that the plates will deliver different ingredients in different order, while. the actuation is continuous and regulated so that all the plates will deliver their measured quantities in constant relation to each other.

When the modified actuating elements are used, the plates not only move material outwardly but have a wave-like motion which tends to agitate the material on the plates and in the hoppers and prevents clogging.

The actuating mechanism may be connected to each of the cam members by separate means, but I preferto provide the clutch mechanism shown for connecting the actuator to all of the cam members.

Attention is particularly called to the alternation of the delivering movements of the several movable plates provided for, whereby measured quantities of the several classes or grades of materials may be delivered to the chute in a selected order, for example, a portion of sand dropping into the chute after a portion of coarse aggregate has dropped,

and the loads on the driving elements may be equally distributed.

What I claim and desire to secure by Letters Patent is:

1. An apparatus of the character described including a plurality of chambers for supporting separate materials and each having a side port, individual slides for each chamber to move material through the ports, pitmen connected to the slides, an operating shaft, and cranks on the operating shaft for connecting the pitmen arranged to operate the slides in progressive order, whereby measured quantities of material are delivered in successive order to efiect a substantially stratified mixture.

2. In apparatus of the character described, a series of hoppers having open bottoms and side ports, a series of plates closing the bottoms of the hoppers and movable to move materials from the hoppers through the ports, a rotating shaft, and a series of crank members mounted at eircumferentially spaced points on the shaft and connected to the several plates for reciprocating the same to successively move materials from the several hoppers, whereby measured amounts of materials are delivered in successive order upon each revolution of said shaft.

In testimony whereof I aflix m signature.

CLIFFORD IFTON. 

